To make the paste, place the lemongrass, chili, turmeric, galangal or ginger, garlic, makrut lime leaves and the oil in a small blender and blend until it is of course paste. Alternatively you can do this in a mortar and pestle.
Heat a large pot on medium heat for 2 minutes. Add 1 tablespoon oil and the curry paste and stir for 30 seconds until fragrant. Add the vegetable stock and eggplant, reduce heat to medium, cover and cook until the eggplant is tender, about 10 minutes.
Meanwhile bring a large pot of salted water to the boil. Add the rice noodles and cook according to package instructions, until al dente. Drain and run under cold water until the noodles are cool.
To the curry base, add the coconut milk, makrut lime leaves, vegan fish sauce or soy sauce, sugar and season with salt and black pepper and stir to combine. Add the tofu and baby bok choy and cook, uncovered, until the tofu is warmed through and the baby bok choy is just tender, 4-5 minutes.
To serve, place the cooled rice noodles into a bowl and ladle the soup, tofu and vegetables over. Top with your chosen toppings and serve warm or at room temperature.